The present invention relates to a method for displaying a color image under various illuminants, and more particularly, to a method for displaying a visually consistent color image regardless of illuminants by removing the influences of chromaticity and luminance of the respective illuminants.
A device-independent color processing method which is a conventional color image reproducing method is based on a device characterization method for setting up the relationship between a standard color signal and a device color signal of the color input and output device. When using this method, a colorimetric color matching can be achieved between an input image and a displayed image, however, the influences exerted due to the changes in the chromaticity and the brightness of the illuminant cannot be avoided since they are not considered at all.
There is a conventional method for compensating for the above problems by applying the color processing technology using a visual color model. In this method, the chromaticity and the brightness of the display device and a printer illuminant are considered. However, the method can be applied under an independent observation condition in which an observation condition of the color image on the display device is not affected by the observation condition of a color printer output material at all. In particular, the observation condition of this method is restricted to the case in which it is dark, namely, it is not affected by the chromaticity or the brightness of the illuminant. Therefore, this method has limitations for applications in a general office environment in which the color image on the display device is observed under an office illuminant. In particular, the above problems of the conventional technologies become bigger as the difference in the chromaticity between a monitor and the illuminant increases. This is because the change in the chromatic adaptation state of an observer is not reflected during observation of the image on the display device and a constant level of light of the illuminant reflected from the surface of the display device is not considered at all.